Handling working pieces in liquids in dental technology

ABSTRACT

Work pieces are treated in pickling liquids especially in dental technology and gold and silver forging for deoxidation purposes. The workpieces are arranged in a removable container swingingly mounted on the cover of the bath apparatus. This avoids the necessity of using material handling equipment such as forceps and tongs.

United States Patent Lea Feb. 19, 1974 HANDLING WORKING PIECES IN LIQUIDS [56] References Cited IN DENTAL CHNOLOGY UNITED STATES PATENTS [75] Inventor: Hans Lea, Frankfurt, Germany 3,121,438 2/1964 Kennedy 134/ 135 1,979,241 11/1934 Albanese 91/63 Asslgneel Deulsche Gold-Ind 494,191 3/1893 La Porte 134/85 silber-scheideanstalt Vormals, 2,162,846 5/1939 Kirchner 148/8 Frankfurt, Germany Sept. 22 Primary Examiner-Morris Assistant ExaminerDale Lovercheck PP N03 291,166 Attorney, Agent, or Firm-Cushman, Darby &

Cushman [30] Foreign Application Priority Data Nov. 26, 1971 Germany 2158637 [57] F F Work pieces are treated 1n prcklmg-hqurds especlally 52 us. 01. 134/25 R, 134/3, 134/25 R, in dental echmbgy and and silver fmging 134/28, 134/31, 4 41 134/85, 134/92, deoxidation purposes. The vvorkpieces are arranged 1n 134/105, 134/135, 134/143, 156/345 a removable contalner swmglngly rnounted on the 51 1111.01 B08b 3/08 the bath aPPaaFUS- P' avmds messty [58] Field of Search 134/2 3, 25 R, 41, 28 31 of using material handling equlpment such as forceps and tongs.

4 Claims, 1 Drawing Figure HANDLING WORKING PIECES IN LIQUIDS IN DENTAL TECHNOLOGY in dental technology and in gold and silver forging technology it is necessary to deoxidize oxidized workpieces of base metal containing noble metal alloys by casting, brazing or annealing. Generally, for this purpose there are used simple ceramic containers, for example porcelain casseroles, which are filled with a suitable picklingliquid. The required heating of the pickling liquid takes place over the flame of a bunsen burner or on an electric hotplate. After the pickling the workpiece must be taken out of the hot pickling liquid with tongs or forceps. In this procedure there is the danger of the formation of a galvanic cell which leads to a copper deposit on the workpiece. Remnants of such copper deposit can, for example, in noble metal working in dental technology bring about disagreeable discolorations in the mouth of the patient. A further disadvantage of this process is the escape of acid vapors injurious to health and corrosive to the iron tools.

It has now been found that the disadvantages of the known processes can be avoided by having the deoxidation take place in a closed apparatus containing the pickling liquid in which the work pieces to be pickled are arranged in a removable container which is fastened in swinging fashion to the cover of the apparatus. This construction permits the user to completely eliminate the additional material handling equipment such as forceps, tongs and the like whose disadvantages are described above.

The workpieces for the pickling are placed by hand in the container mounted in swingable manner on the cover of the apparatus and together with the container are lowered into the pickling liquid. Thereupon the cover of the apparatus joined to the swingable container returns in guided manner to its closed position and closes the apparatus so tightly with its sealing ring during the pickling process that no vapor of the pickling fluid can escape outside.

After the end of the pickling process, the user raises the cover of the apparatus high whereby in guided manner, the workpieces arranged in the swingable container are removed from the pickling liquid. During these processes the pickling fluid which is found in the container in' the pickling process flows back through openings on the bottom side of the container in the apparatus. By a hand motion the user turns the cover of the apparatus 180 so that the bottom side of the cover is arranged below the container with the workpieces. In this situation the bottom side of the cover serves as a collecting vessel for residues of the pickling fluid still dropping from the container. In this position the user goes with the workpieces to a water tap with a discharge basin. He swings the cover about over the discharge basin with a hand motion and can now cleanse the pickled workpieces in the flowing water jet from remaining residues of pickling liquid,

A further possibility in rinsing the workpieces is that the user of the apparatus instead of employing the flowing water jet employs a prepared vessel containing water. In this case he swings the cover of the apparatus about by a hand motion after which he can likewise bririg about an appropriate rinsing by alternating immersion in and raising of the container above the water bath.

In both cases after the rinsing process for the return of the workpieces to the working place the cover of the apparatus is so turned by a hand motion that its bottom side comes to rest under the container with the workpieces. Thus, the water dropping from the container or from the workpieces is caught on the bottom side of the cover.

At the working place the now pickled and cleansed workpieces can be withdrawn from the container with the fingers, again without utilization of assisting apparatus such as tongs or forceps and the further working can be carried out. The flat top side of the cover makes possible assembly at the working place so that both hands are free.

A further characteristic of the invention is that the pickling fluid condensing on the relatively cool bottom side of the cover is returned again into the deoxidation vessel.

The single FIGURE of the drawing is a crosssectional view of an apparatus for carrying out the invention.

Referring more specifically to the drawings there is provided a container 1 for a bath, e.g., a pickling bath consisting of sulfuric acid or another pickling agent.

The container is heated by-a heater 7. Inside the bath container 1 there is situated another container 2 which contains workpieces, e.g., dental tools. The container 2 is swingingly connected with the cover 3 by support 4. The container 2 in its bottom has openings 5 through which it is guaranteed that the pickling fluid can flow around the workpieces to be treated.

After the pickling the cover is raised up whereupon simultaneously the container 2 is removed from the pickling fluid. Since the container 2 is swingably mounted on the supports 4 the person undertaking the working process can bring the treated workpieces in the range of his sight by swinging the container 2 and thereby control whether the surface properties of the treated pieces are unobjectionable.

In the pickling process in the heated pickling bath there takes place an evaporation of the liquid. It is undesired that this vapor. reach the working space. For this reason it is suitable to condense this vapor on the relatively cool surface of the bottom of the cover and return it again into the bath container 1. Therefore, there is provided an additional conical inner cover 6 on whose surface a substantial part of the evaporated liquid condenses and then flows back again into the bath container 1. A supplementation of the pickling liquid is practically not necessary because the vapor developed condenses again in the apparatus and is returned into the bath container 1.

What is claimedis: I

1. A process of deoxidizing gold or silver on dental workpieces comprising providing a liquid pickling bath in a first container, providing a cover suitable for closing said first container, placing said workpieces in a second smaller container swingably attached to said cover, moving said second container into said first container so that the workpieces are in contact with said pickling bath and the cover closes said first container and thereafter raising the cover and removing said second container from the pickling bath, turning the cover of the first container sufficiently, after the second container is removed from the pickling bath, that the bottom of the cover is below said second container, and

3. A process according to claim 1 wherein the bottom side of the cover is conical and said process comprises condensing vapors from said pickling bath on said conical bottom side and returning them to the bath.

4. A process according to claim 1 comprising the subsequent step of rinsing the workpieces in said second container with water. 

2. A process according to claim 1 wherein openings are present in the bottom portion of said second container, said opening being smaller than the smallest dimension of said workpieces and said process inclUdes passing pickling liquid through said openings from the bath into the second container and back into the bath.
 3. A process according to claim 1 wherein the bottom side of the cover is conical and said process comprises condensing vapors from said pickling bath on said conical bottom side and returning them to the bath.
 4. A process according to claim 1 comprising the subsequent step of rinsing the workpieces in said second container with water. 